Heat exchange installation



Dec. 31, 1963 A, H ET HEAT EXCHANGE INSTALLATION Filed Feb. 24, 1959 FIG. IA

INVgNTOR: ANDR HUET Q A ATTORNEY United States Patent 3,115,870 HEAT EXCHANGE INSTALLATION Andr Huet, 48 Ave. du President Wilson, Paris, France Filed Feb. 24, 1959, Ser. No. 795,270 Claims priority, application France Mar. 10, 1958 5 Claims. (Cl. 122-32) The present invention relates to heat exchangers and particularly to unitary steam generating and superheating apparatus embodying all of the heat exchangers in one or several casings through which a heating fluid is directed.

In an earlier application Serial No. 695,851, filed November 12, 1957, applicant has described a heat exchange installation destined, for instance, to the use of heat released in a nuclear reactor and which installation was divided into a large number of elementary heat exchangers, each having the aspect of a vertical duct-casing containing all the necessary elements for the production of steam.

In the patent application Serial No. 702,048 of December 11, 1957, entitled Fragmentation into Elements of a Heat Exchange Installation, now Patent No. 2,983,260, applicant described an installation of this nature in which individual elements constituting each elementary heat exchanger, namely: an economizer, a vaporizer and a superheater for a first stage of steam production at low pressure, and a second set of similar elements to constitute a high pressure stage, is encased within two or more fluid ducts joined in series in such a manner that a first ductcasing contains, for instance, the whole group of low pressure elements, as Well as part of the high pressure elements, whereas a second duct-casing contains the remainder of the high pressure elements. It was also contemplated that any other distribution of the elements forming a complete unit could be adopted.

According to the present invention, the water circulation in the thermic exchange installation takes place under pressure With forced circulation. This permits increasing the velocity of the Water-steam volume Within the installation and, consequently, decreasing the area of the exchange surfaces and the height of the vertical duct-casings. Under these conditions applicant proposes a new distribution of the elements within the duct-casings. According to this distribution, each complete unit comprises at least tWo duct-casings through which the gases flow in parallel. One, or possibly several, duct-casings contain, for example, a low pressure economizer and vaporizing tubes supplying steam from a first pressure stage and also the vaporizing tubes of a second pressure stage. A second duct-casing (or a third, if there are two in the first set) contains high and low pressure superheaters and part of the economizers.

In an installation of this kind, the water-steam separation at each pressure stage, instead of being eifected in a water drum as part of the vaporizers contained in the ductcasing, such as described in the previous applications of the applicant, is effected outside the duct-casings in a separate Water and steam separating drum and this drum is common to many individual units of the complete thermal installation (each unit having vaporizing, generating and superheating elements).

The following description when read in conjunction with the accompanying drawings will afford an understanding of how an illustrative embodiment of the invention can be carried out.

FIGURE 1 is a schematic diagram illustrating the invention, one complete component of economizer, generating and super heating elements in both a low and high pressure stage being shown in full lines, while other similar components are fragmentarily illustrated in dotted lines. FIGURE 1A is a diagrammatic plan view.

According to one way of executing the invention, as shown in FIGURE 1 which illustrates a forced circulation system, each individual unit of the installation embodying two steam stages includes two vertical duct-casings 10 and 12 through which the hot fluid such as gases flow in parallel from top to bottom in the direction of the arrows F. The casing 10 contains, for instance, a low pressure economizer 14, a low pressure evaporator 16, a high pressure economizer 18 and a high pressure vaporizer 20. In the second casing 12 is part 21 of an economizer asso ciated with either the high pressure element 18 or the low pressure element 14, a low pressure superheater 22 and a high pressure superheater 24. The water and steam circulation in the element is controlled by means of circulation pumps; 26 for low pressure and 28 for high pressure.

Steam leaving the low pressure vaporizer 16 through a duct 30 is sent into a drum 32 where the separation of Water and steam takes place. Low pressure steam leaves via a main 34 and passes into the low pressure superheater 22, whence it is led a main 36 into a low pressure header 38. Water retaken at the base of the drum 32 by pump 26 is sent by a line 33 to the inlet end of the low pressure vaporizer 16. Water coming from an associated turbine condenser or make up water are introduced through a line 35 into the low pressure economizer 14.

Likewise in regard to the high pressure stage, steam leaving the high pressure vaporizer 20 via a line 40 passes into a drum 42 whence water is retaken by pump 28 to be injected by a line 43, for instance, into the high pressure economizer 18. Steam leaving drum 42 via a line 44 passes into the high pressure superheater 24 whence it leaves via a line 46 and passes into a header 48 for high pressure steam. Condenser water or feed water are introduced into the inlet end of the economizer section 21 through a line 45.

In accordance with the invention, the pumps 26 and 28 are by-passed by ducts 27 and 29 in such a manner that, in case of stoppage of the pumps, the circulation may yet be eliected at each pressure stage.

The distribution of the economizers between casings 10 and 12 could be other than that shown in the drawings, and the economizer located at the base of the casing 12 could be a serial part of either low pressure economizer 14 or of high pressure economizer 20.

All the inlets or outlets of the fluids in the organs contained in the casings 10 and 12 are preferably above or below the end closures provided for the casings.

Each separator drum whether high or low pressure 32 or 42 is common to a group of several individual economizer and generating units, such as that described as being contained within casings 10 and 12. The same is true With respect to the steam headers 38 and 48 which are common to and fed by superheaters in a number of casings 12. This is shown in FIGURE -1A.

Modifications in details may be made without departing from the scope of this invention.

What I claim is:

l. A heat exchange installation constituted by a plurality of individual units containing heat absorbing elements necessary for the production at diiferent pressure stages of steam derived from water, each individual unit comprising at least two vertical cylindrical elongated housings; means for admitting a hot fluid to said housings at one end thereof and for withdrawing said fluid from their other ends, one of said cylinders comprising a first evaporator and economizer connected in series and a second evaporator and economizer also connected in series, the other of said cylinders comprising a first and second superheater, a first steam and water drum connected to said first evaporator, means connecting said drum to said first superheater, a second steam and water drum, means connecting said second drum to said second evaporator, and means connecting said second drum to said second superheater.

2. A heat exchange installation as recited in claim 1 wherein said. first steam and water drum is connected to said first economizer by a recirculating conduit containing a recirculation pump.

3. A heat exchange installation as recited in claim 1 wherein said second steam and water drum is connected to said second evaporator by a recirculation conduit containing a recirculation pump.

4. A heat exchange installation as recited in claim 2 wherein a bypass conduit is. connected around said recirculat'ion pump to provide for material circulation through said recirculation conduit on failure of said pump.

5. A heat exchange installation as recited in claim 3 wherein a bypass conduit is connected around said recirculation pump to provide for material circulation through said recirculation conduit on failure of said pump.

References Cited in the file of this patent UNITED STATES PATENTS 1,803,081 Uhle et al Apr. 28, 1931 2,189,443 Brantly Feb. 6, 1940 2,321,390 Juzi June 8, 1943 2,346,179 Meyer et al Apr. 11, 1944 2,547,589 Marshall Apr. 3, 1951 2,702,026 Dalin Feb. 15, 1955 2,796,050 Rehm June 18, 1957 2,867,983 Armacost Jan. 13, 1959 2,982,263 Villiers et a1. May 2, 1961 FOREIGN PATENTS 1,157,405 France Dec. 30, 1957 

1. A HEAT EXCHANGE INSTALLATION CONSTITUTED BY A PLURALITY OF INDIVIDUAL UNITS CONTAINING HEAT ABSORBING ELEMENTS NECESSARY FOR THE PRODUCTION AT DIFFERENT PRESSURE STAGES OF STEAM DERIVED FROM WATER, EACH INDIVIDUAL UNIT COMPRISING AT LEAST TWO VERTICAL CYLINDRICAL ELONGATED HOUSINGS; MEANS FOR ADMITTING A HOT FLUID TO SAID HOUSINGS AT ONE END THEREOF AND FOR WITHDRAWING SAID FLUID FROM THEIR OTHER ENDS, ONE OF SAID CYLINDERS COMPRISING A FIRST EVAPORATOR AND ECONOMIZER CONNECTED IN SERIES AND A SECOND EVAPORATOR AND ECONOMIZER ALSO CONNECTED IN SERIES, THE OTHER OF SAID CYLINDERS COMPRISING A FIRST AND SECOND SUPERHEATER, A FIRST STEAM AND WATER DRUM CONNECTED TO SAID FIRST EVAPORATOR, MEANS CONNECTING SAID DRUM TO SAID FIRST SUPERHEATER, A SECOND STEAM AND WATER DRUM, MEANS CONNECTING SAID SECOND DRUM TO SAID SECOND EVAPORATOR, AND MEANS CONNECTING SAID SECOND DRUM TO SAID SECOND SUPERHEATER. 